Hadith 1:189

Narrated As-Sa'ib bin Yazid:

My aunt took me to the Prophet and said, "O Allah's Apostle! This son
of my sister has got a disease in his legs." So he passed his hands on
my head and prayed for Allah's blessings for me; then he performed
ablution and I drank from the remaining water. I stood behind him and
saw the seal of Prophethood between his shoulders, and it was like the
"Zir-al-Hijla" (means the button of a small tent, but some said 'egg
of a partridge.' etc.)